From a41f08402e78e9066551d72a9835a352db4069e4 Mon Sep 17 00:00:00 2001
From: dzwdz
Date: Wed, 6 Oct 2021 06:43:27 +0000
Subject: init printf: implement %x
---
src/init/main.c | 2 +-
src/init/stdlib.c | 15 +++++++++++++++
2 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/src/init/main.c b/src/init/main.c
index 7c827eb..2029bc9 100644
--- a/src/init/main.c
+++ b/src/init/main.c
@@ -29,7 +29,7 @@ int main(void) {
fs_test();
test_await();
- printf("%s\n", "printf test");
+ printf("%s %x\n", "printf test", 0xACAB1312);
char c;
while (_syscall_read(tty_fd, &c, 1, 0))
diff --git a/src/init/stdlib.c b/src/init/stdlib.c
index 876c74c..a60854b 100644
--- a/src/init/stdlib.c
+++ b/src/init/stdlib.c
@@ -42,6 +42,21 @@ int printf(const char *fmt, ...) {
_syscall_write(0, s, strlen(s), 0);
total += strlen(s);
break;
+
+ case 'x':
+ unsigned int n = va_arg(argp, int);
+ size_t i = 4; // nibbles * 4
+ while (n >> i && i < (sizeof(int) * 8))
+ i += 4;
+
+ while (i > 0) {
+ i -= 4;
+ char h = '0' + ((n >> i) & 0xf);
+ if (h > '9') h += 'a' - '9' - 1;
+ _syscall_write(0, &h, 1, 0);
+ total++;
+ }
+ break;
}
seg = fmt;
break;
--
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